Mapping Hacks

Build Your Own Car Navigation System with GpsDrive #63

Chapter 5, Mapping with Gadgets

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HACK

Adding Your Own Maps

Since GpsDrive maps are regular images, you can create your own maps. A

GpsDrive map is a 1280 × 1024 pixel GIF image. You can use the Misc

Menu

➝ Maps ➝ Import map tool to import a map, or you can directly edit

the map_koord.txt file.

Any image named map_file

nnnn (where nnnn is replaced with a number) can

be used as a GpsDrive map. You can also edit the maps that GpsDrive down-

loads from Expedia. Maps are stored in your home directory in ./gpsdrive.

Each line contains a filename, the latitude at the center of the map, and a

scale. So you can customize a map by taking an existing map and adding

your own annotations. If you select “Auto Best Map” from the checkboxes

on the left side of the screen, GpsDrive will automatically pick the best scale

for the map. You can then set the largest-scale maps to be regular photo-

graphs. It’s fun to pull up at your destination and have your navigation sys-

tem show you a picture.

Playing Nice with Others

Since GpsDrive can use gpsd [Hack #57], you can run other GPS-aware applica-

tions in conjunction with your navigation system. For example, you can run

Figure 5-46. Zooming in while sitting still shows the effects of GPS “drift”

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Chapter 5, Mapping ...